The lesbian mothers are currently being cast for the episode, which will air in 2014, and production is to begin next week.

After finding out the news through a tweet by bisexual actress Evan Rachel Wood, Cyrus tweeted her excitement at the news to her almost 12.5 million fans.

The actress and singer, and former Disney Channel star said: “Is this true?!?!?! I commend Disney for making this step into the light of this generation. They control… so much of what kids think! Life isn’t bright sets & wardrobe & kids becoming superstars! This is INSPIRING”.